I'm taking my 400EX to the Cinder's in Flagstaff next month. The elevation is around 7000 feet. Anybody got any jetting recommendations? My mods are: White Brother's filter, rev box, E-series slip on(18 discs), FMF Powerbomb header, XR cam, 172 main, 45 pilot, needle moved up one notch, and no airbox lid. Any help will be appreciated. Thank's in advance.

 

when I went to Col. last summer to go riding I was told by a dealer in the area to drop 1 main jet size for every 1500 ft and 1 pilot size for every 3000 ft difference from the hight that you are jetted for. I did that and it ran good, with my 440ex. And we a lot of fun riding the trails.

 

Thank's for the advise. That sounds like a good rule of thumb. Anyone else have any opinions or experiences?

 

TTT

 

Use Stock pilots and clip settings. I'd go 155 and lower. Our group 7 400's all runs 162-165 mains. I fouled a plug at 165 and am dropping to 160. Nobody has a cam though. Nobody runs a lid either..